JPH11294622A - Driving device of solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely regulate a pressure into a target at regulating hydraulic pressure by correcting driving current for obtaining the target pressure based on calibration information obtained based on correlation of hydraulic pressure and driving current in a solenoid valve in which the driving current required for obtaining the target pressure is larger. SOLUTION: In an automatic transmission 2, feed oil pressure to respective frictional engaging elements such as clutch or brake is controlled by a plurality of solenoid valves under control of a control device 3, so as to build up required shift steps. Based on calibration information obtained based on correlation of driving current and hydraulic pressure given to the solenoid valve by the control device 3, driving current for obtaining target hydraulic pressure obtained from correlation to be a base, and this device control so as to give the corrected driving current to the solenoid valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve driving apparatus, and more particularly to a solenoid valve used for controlling an operating oil pressure in an automatic transmission for a vehicle, for example, in which a characteristic variation due to a variation in a set load of a return spring or the like is reduced. Related to correction technology.

[0002]

2. Description of the Related Art Conventionally, in automatic transmissions for vehicles,
There is known a mechanism that changes the opening area of an oil path by displacing a plunger of a solenoid valve, thereby adjusting the oil pressure for various frictional engagement elements (clutch, brake, etc.). Here, the solenoid valve is generally provided with a return spring (elastic member) for urging the plunger in one direction, and the magnetic force of the solenoid valve is applied against the urging force of the return spring. However, since a large variation occurs in the set load of the return spring, an adjustment mechanism (adjustment screw) for adjusting the set load is provided, and the set load is individually manually adjusted by the adjustment mechanism to set a reference value. Has been performed in a line process during manufacturing and assembling.

[0003]

However, the provision of the adjusting mechanism in the solenoid valve as described above increases the cost and the size of the solenoid valve. In the configuration in which the set load is adjusted by manually operating the adjustment mechanism, there is a problem that the number of adjustment steps is increased.

Therefore, instead of individually adjusting the set load of the return spring, a system for correcting the drive current in accordance with the deviation of the correlation between the drive current and the hydraulic pressure due to the variation of the set load may be used. Is unnecessary, and manual adjustment of the set load is not required. However, the design characteristics of the solenoid valve
In spite of the characteristic shown by the solid line in FIG. 9, the characteristic shown by the dotted line in FIG. 9 may actually appear due to the variation in the set load. In this case, the current applied to the solenoid valve Is set to zero, the target hydraulic pressure cannot be obtained, and a negative current is required, so that the target hydraulic pressure cannot be substantially obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a solenoid valve driving device capable of surely adjusting a target pressure (or flow rate) by correcting a driving current.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a solenoid valve driving device for adjusting a fluid flow rate or a fluid pressure, wherein a drive amount of a fluid flow rate or a fluid pressure and a drive current of a solenoid valve are controlled. A solenoid valve that requires a larger drive current to obtain a target flow rate or target pressure than a reference correlation, and calibration information previously obtained based on the correlation between the fluid flow rate or fluid pressure and the drive current in the solenoid valve. And a current control means for correcting a drive current for obtaining a target flow rate or a target pressure obtained from the reference correlation, and supplying the corrected drive current to the solenoid valve.

According to this configuration, the solenoid valve has a variation in the correlation between the flow rate or the pressure and the drive current due to a variation in the set load or the like.
The target flow rate is manufactured by manufacturing the drive current for obtaining the target flow rate or the target pressure to be larger than the reference correlation, and correcting the drive current to be larger than the drive current obtained from the reference correlation. Alternatively, a pressure is obtained.

[0010] In the invention described in claim 2, the calibration information is based on the reference current and the drive current when the drive current is feedback-controlled so as to match the target flow rate or target pressure for inspection. The configuration is obtained in advance based on a deviation from a drive current corresponding to a target flow rate or a target pressure for inspection. According to this configuration, the flow rate or the pressure is actually adjusted in advance by the solenoid valve, and the drive current is increased or decreased while the actual value of the flow rate or the pressure is compared with the target flow rate or the pressure for the test. The drive current at which the flow rate or pressure is actually obtained is determined. Then, on the reference correlation, the difference between the drive current corresponding to the target flow rate or pressure for inspection and the drive current when the target flow rate or pressure for inspection is actually obtained is relative to the reference correlation. Required as a correction request. Here, the characteristic of the solenoid valve is such that the drive current required to obtain the target flow rate or target pressure is limited to a larger characteristic than the reference correlation, so that the inspection target flow rate or pressure is actually The obtained drive current is larger than the drive current corresponding to the inspection target flow rate or pressure on the reference correlation, and the drive current correction request is an increase correction.

According to the third aspect of the present invention, the flow rate or the pressure of a fluid different from the flow rate or the pressure to be adjusted by the solenoid valve is adjusted to obtain the calibration information in advance, and the calibration information is actually determined by the flow rate or the pressure. Is converted into a value for a fluid to be adjusted and used. According to such a configuration, for example, when obtaining calibration information of a solenoid valve for adjusting the flow rate or pressure of oil, the calibration information is obtained by adjusting the flow rate or pressure of air that is easy to handle, and the actual flow rate or When adjusting the pressure, the calibration information obtained by adjusting the air is converted and used for oil.

[0010]

According to the first aspect of the present invention, since the correction of the drive current is limited to the increasing direction, a negative current is not required as a correction result, so that the solenoid valve is not required. Even if there is a variation, there is an effect that the target flow rate or pressure can be reliably obtained by correcting the drive current.

According to the second aspect of the invention, there is an effect that the calibration information can be individually obtained with high accuracy by knowing the actual correlation between the flow rate or pressure in the solenoid valve and the drive current. According to the third aspect of the invention, when the flow rate or the pressure is adjusted by the solenoid valve in order to know the actual correlation between the flow rate or the pressure in the solenoid valve and the drive current, a fluid (e.g., air) which is easy to handle is used. By making adjustments, calibration information can be obtained with a simple system, while performing actual adjustment in the drive device, by converting and using the calibration information,
There is an effect that the correction accuracy can be secured.

[0012]

Embodiments of the present invention will be described below. FIG. 1 shows a hydraulic automatic transmission for a vehicle including a drive device for a solenoid valve according to the present invention. In FIG. 1, a torque of an engine 1 mounted on a vehicle (not shown) is transmitted to driving wheels (not shown) via an automatic transmission 2.
The automatic transmission 2 may be either a continuously variable transmission or a stepped transmission.

Further, a control device 3 (in the figure, denoted as A / TC / U) for performing a shift control of the automatic transmission 2 includes:
By incorporating a microcomputer including a CPU, a RAM, a ROM, and the like, and controlling a plurality of solenoid valves that adjust supply hydraulic pressure to each friction engagement element (clutch, brake, etc.) of the automatic transmission 2, Automatically controls the gear.

The solenoid valve changes the opening area of the oil path by displacing a plunger (movable iron core) biased by a return spring by a magnetic force against the biasing force of the return spring. Thus, the hydraulic pressure supplied to each friction engagement element is controlled. For example, as shown in FIG. 2, the solenoid valve is configured to increase the drain amount and decrease the hydraulic pressure in accordance with an increase in the applied drive current. Direction requiring larger drive current to obtain the same oil pressure (shaded area)
It is manufactured so that there is a variation only in. That is,
It is inevitable that the set load of the return spring will vary from the manufacturing point of view.However, due to the setting of tolerance, etc., the variation will only occur in the direction that requires a larger drive current to obtain the same hydraulic pressure than the reference correlation. Variations in the direction in which the required drive current becomes smaller than the reference correlation do not occur.

The solenoid valve may have a characteristic of increasing the hydraulic pressure in accordance with an increase in the drive current. In this case as well, as shown in FIG. Is manufactured so as to vary only in a direction (a shaded area) where a large drive current is required to obtain. The control device 3 determines a target hydraulic pressure for each friction engagement element and, based on the correlation between the drive current i applied to the solenoid valve and the hydraulic pressure, determines a drive current i corresponding to the target hydraulic pressure as a target current (basic value). Is output to the solenoid valve, and the energization control amount of the solenoid (for example, transistor on-duty) is feedback-controlled so that the current actually flowing through the solenoid valve matches the target current.

More specifically, the energization of the solenoid is feedback-controlled by the configuration shown in FIG. In FIG. 4, the target current calculation unit 51
A target current (basic value of the drive current) corresponding to the target oil pressure at that time is calculated from a reference correlation between the target oil pressure and the drive current stored in advance.

The median value setting section 52 sets a reference duty (median value) corresponding to the target current, and outputs this as a feedforward correction amount (F / F correction amount). On the other hand, in the feedback correction unit 53, the solenoid valve 5
Then, a deviation between the detected value of the current actually flowing and the target current is obtained, and based on the deviation, a feedback correction amount (F / B correction amount) is output by a proportional, integral and differential (PID) control operation.

Then, the feedforward correction amount (F
/ F correction amount) and the feedback correction amount (F / B correction amount), the result (duty) of which is a transistor (not shown) that controls the amount of current supplied to the solenoid valve 5.
The ON / OFF control of the transistor is performed according to the duty, so that the amount of energization of the solenoid valve 5 is controlled according to the ON time ratio.

The current detection of the solenoid valve 5 is output as a terminal voltage of a resistor provided for current detection,
The voltage is input to an A / D converter 56 via a low-pass filter 55 and A / D converted. The voltage data after the A / D conversion is converted into current data by the voltage / current converter 57. Then, the detection data of the current is subtracted from the target current, and the deviation obtained by the subtraction processing is output to the feedback correction unit 53 as an error amount (control deviation).

A correction amount setting section 58 is provided.
As shown in FIG. 5, the correction amount setting section 58 sets a correction current (correction value) according to the target current calculated by the target current calculation section 51, and sets a correction gain according to the target current. Is set, and the result of multiplying the correction current by the correction gain is used as the final correction current. Then, the final correction current is added to the target current calculated by the target current calculation unit 51, and the addition corrected target current is input to the median value setting unit 52 (current control means). Further, the output of the voltage-current converter 57 is corrected by the final correction current,
An error amount (control deviation) is calculated as a deviation between the corrected detection result and the target current calculated by the target current calculation unit 51.

The correction current set by the correction amount setting section 58 is for correcting the variation in the correlation between the drive current and the hydraulic pressure due to the variation in the set load of the solenoid valve 5 and the like. As described above, the target current output to the median value setting section 52 is corrected in order to cope with the characteristic variation of each solenoid valve 5 without changing the setting characteristic of the target current in 51.

By the way, the variation in the correlation between the drive current and the hydraulic pressure in the solenoid valve 5 is made to occur only in a direction requiring a larger drive current for the same hydraulic pressure than the reference correlation as described above. Because
The correction current set in the target current calculator 51 is
The correction value in the increasing direction (plus) is obtained over the entire range of the target current calculated by the target current calculation unit 51. Therefore, the result of adding the correction current to the target current calculated by the target current calculation unit 51 does not become a negative value, and the drive current corresponding to the target oil pressure is always output as a positive value, and the solenoid valve 5 can be reliably controlled to a value corresponding to the target hydraulic pressure.

The correction of the drive current by the above correction current can compensate for the variation in the set load of the return spring of the solenoid valve 5, so that the solenoid valve 5 in the present embodiment has a function of adjusting the set load. Not been. When the actual current of the solenoid valve 5 is directly compared with the target current calculated by the target current calculator 51, feedback control is performed so as to match the target current calculated by the target current calculator 51. Since the correction by the correction current does not function, the detection result of the current is corrected by the correction current,
By comparing the detected current value obtained by subtracting the correction current and the target current calculated by the target current calculation unit 51,
The feedback control is performed using the deviation from the target current as an error amount in the same manner as when the correction by the correction current is not performed.

The correction current set according to the target current in the correction amount setting section 58 is used to obtain the target pressure when the air pressure is adjusted by the solenoid valve in the assembly line process of the automatic transmission. Is calculated in advance as a deviation between the command value of the drive current required for the target pressure and the basic value (reference drive current) of the drive current corresponding to the target pressure. In order to convert the oil pressure to a value suitable for adjusting the oil pressure, the oil pressure is corrected by the correction gain.

That is, in order to individually detect the correlation between the pressure in the solenoid valve and the drive current, it is preferable to adjust the oil pressure in the same manner as in the actual machine, but in the assembly line process, the oil is supplied to the solenoid valve. If the supply configuration is adopted, the size of the system becomes large, and contamination by splashing of oil also poses a problem. Therefore, the correction request is detected by adjusting the pressure of the air that is easy to handle and does not cause contamination, and the deviation of the correction request due to the difference between the air and the oil is compensated by the correction gain, and the air is adjusted to the air. By correcting the correction current obtained and stored in advance with the correction gain,
When the oil pressure is adjusted, it is converted to a correction current suitable for the oil pressure. However, the correction current converted for the oil by the multiplication of the correction gain may be stored in advance.

The characteristics of the correction gain with respect to the drive current shown in FIG. 5 are based on the assumption that the hydraulic pressure increases as the drive current increases. FIG. 6 shows an inspection device 11 used for detecting the correction current in the assembly line process of the automatic transmission, and the inspection device 11 is integrated in a case of the automatic transmission 2 in a later process. An A / T unit 6 including a plurality of solenoid valves 5 to be attached to the control device 3 and the control device 3 is set. After an inspection process by the inspection device 11, the A / T unit 6 Attached in the case.

The A / T unit 6 is connected to the inspection machine 11.
An air pressure source 12 (fluid pressure source) for supplying a constant air pressure to each of the solenoid valves 5 is provided. Then, the air whose pressure has been adjusted by each solenoid valve 5 is individually introduced into the inspection machine 11 through the pipe 11a, and the inspection machine 11
The air pressure as a result of adjustment is detected for each solenoid by an air pressure sensor built in the microcomputer.

The inspection machine 11 increases or decreases the target current (indicated value of the drive current) and outputs it to the control device 3 so that the detected air pressure matches the predetermined target pressure. A correction current as calibration information is calculated from a target current (a drive current instruction value) at the time, and the correction current is stored in a nonvolatile storage medium (for example, a flash memory) of the control device 3.
Is written together with the control program.

The correction current may be obtained from the current flowing through the actual solenoid valve when the pressure matches the target pressure. However, as described above, the correction current is obtained from the instruction value of the drive current. For example, there is no need to feed back the current value of the solenoid valve from the control device 3 to the inspection device 11, and the man-hour and maintenance can be simplified. Here, the operation of the inspection machine 11 will be described with reference to the flowchart of FIG.

First, in S1, supply of air pressure to each solenoid valve is started. In S2, a drive current corresponding to the target pressure (1) set in advance for inspection is set based on the correlation between the target oil pressure and the drive current in the target current calculator 51, and the drive current (reference drive current) is set. )
Is output to the control device 3 as an initial value of the target current (instruction value), and a drive current corresponding to the target current is supplied to the solenoid valve 5 via the control device 3.

In S3, the air pressure adjusted by the solenoid valve 5 is detected by an air pressure sensor built in the inspection machine 11. In S4, it is determined whether or not the air pressure detected in S3 substantially matches the target pressure (1). When the actual air pressure does not coincide with the target pressure (1), S5
To determine whether the value obtained by subtracting the target pressure (1) from the actual air pressure is a positive value, thereby determining whether the actual air pressure is higher or lower than the target pressure (1). Determine.

If the value obtained by subtracting the target pressure (1) from the actual air pressure is a positive value and the actual air pressure is higher than the target pressure (1), the process proceeds to S6, where the target current is reduced. The correction is performed by a predetermined value in the direction in which the air pressure decreases, and if it is lower, the process proceeds to S7, where the target current is corrected by the predetermined value in the direction in which the air pressure increases, and the correction result is output to the control device 3. . That is, the target current (indicated value of the drive current) is feedback-controlled so that the actual air pressure coincides with the target pressure. The feedback control operation includes proportional and integral PI operations, and proportional, integral and differential PI operations.
A configuration using the D operation may be adopted.

When the actual air pressure becomes substantially equal to the target pressure (1) by the correction of the target current, S4
To S8, and in S2, the reference drive current (initial value of the target current) set as corresponding to the target pressure (1) and the target pressure (1) as a result of the feedback control in S3 to S7. The difference ΔI (1) (= [target current after feedback] − [initial value]) from the corresponding target current is calculated.

Here, as described above, since the characteristics of the solenoid valve 5 are manufactured so as to vary only in the direction requiring a drive current larger than the reference characteristic, [target current after feedback] ≧ [initial current] Value], and the difference ΔI (1) is calculated as a positive value.
In S9, a drive current corresponding to a target pressure (2) different from the target pressure (1) is obtained from the reference correlation,
This drive current is output to the control device 3 as an initial value of the target current.

In S10, similarly to S3 to S7,
The target current is feedback-controlled so that the actual air pressure matches the target pressure (2). In S11, a difference ΔI (2) between the target current at which the target pressure (2) is actually obtained as a result of the feedback control in S10 and the initial value of the target current set in S9 is calculated. Also in this case, the difference ΔI (2) is calculated as a positive value based on the variation characteristics of the solenoid valve 5.

In S12, based on the above-mentioned ΔI (1), ΔI (2) and the initial value of the target current when these are obtained,
The correction current (calibration information) corresponding to the target current is, for example, shown in FIG.
As shown in FIG. as mentioned above,
With a configuration in which the request for the entire correction current is estimated from at least two data points, the correction current can be accurately estimated when the correction request is not a uniform value. Therefore, three or more target pressures may be set, and the drive current command value when the actual air pressure becomes the target pressure may be obtained for each of them as the basic data for the interpolation calculation.

It is clear that the interpolation is not limited to linear interpolation. In S13, it is determined whether or not the correction current calculated in S12 is within a predetermined range. If it is within the predetermined range, it is determined that the calibration information has been correctly obtained, and the process proceeds to S14. In S14, the control program for the solenoid is written into a storage medium (for example, a flash EEPROM) of the control device 3 and, at the same time, the calculated correction current is written and stored as a correction current in the correction amount setting section 58.

The data written as the correction current in the correction amount setting section 58 is a correction request when adjusting the air pressure. If the correction current is used as it is when adjusting the oil, the oil pressure can be accurately adjusted. Cannot control to target pressure. Therefore, as described above, by multiplying the correction current by the correction gain, the correction current is converted to a value suitable for hydraulic control and used.

In the above-described embodiment, a unit in which the plurality of solenoid valves 5 and the control device 3 are unitized
The configuration is such that the solenoid valve 5 is set in the inspection machine as a single item, and the calibration information (correction current) for each solenoid valve 5 is calculated, and the calibration information for each solenoid valve 5 is stocked. In addition, when the solenoid valve 5 and the control device 3 are unitized, the calibration information of the solenoid valve 5 combined with the control device 3 may be output.

In the above embodiment, the solenoid used for adjusting the hydraulic pressure in the automatic transmission has been described. However, a solenoid valve used for adjusting the flow rate may be used. The drive current of the solenoid valve is feedback-controlled to obtain the flow rate, and the difference between the reference drive current corresponding to the target flow rate and the drive current instruction value when the actual air flow rate becomes equal to the target flow rate is obtained. What is necessary is just to set it as the structure which calculates | requires a correction current.

Further, the inspection machine 11 may also be configured to adjust the flow rate or pressure of the oil so as to obtain the calibration information as a result of adjusting the flow rate or the pressure of the oil. The correction of the correction current by the correction gain in the quantity setting unit 58 is omitted, and the inspection machine 11 may have a built-in oil pressure sensor instead of the air pressure sensor.

[Brief description of the drawings]

FIG. 1 is a view showing an automatic transmission for a vehicle including a drive device for a solenoid valve according to the present invention.

FIG. 2 is a diagram showing a variation range of a solenoid valve in the embodiment.

FIG. 3 is a diagram showing a variation range of a solenoid valve in the embodiment.

FIG. 4 is a block diagram showing a driving device of a solenoid valve in the automatic transmission.

FIG. 5 is a block diagram showing details of a correction amount setting unit in the driving device.

FIG. 6 is a diagram showing an inspection machine for obtaining a correction current by air pressure adjustment in the embodiment.

FIG. 7 is a flowchart showing processing contents in the inspection machine for detecting a correction current in the embodiment.

FIG. 8 is a diagram showing characteristics of a correction current in the embodiment.

FIG. 9 is a diagram showing an example of a variation characteristic of a conventional solenoid valve.

[Explanation of symbols]

 3 Control device 5 Solenoid 6 A / T unit 11 Inspection machine 12 Air pressure source 51 Target current calculation unit 52 Median value setting unit 53 Feedback correction unit 58 Correction amount setting unit

Claims (3)

[Claims] A solenoid valve driving device for adjusting a fluid flow rate or a fluid pressure, wherein a target flow rate or a target pressure is set to be smaller than a reference correlation between the fluid flow rate or the fluid pressure and a drive current of the solenoid valve. A solenoid valve that requires a larger drive current to obtain, and a target obtained from the reference correlation based on calibration information obtained in advance based on a correlation between a fluid flow rate or a fluid pressure in the solenoid valve and the drive current. Current control means for correcting a drive current for obtaining a flow rate or a target pressure, and supplying the corrected drive current to the solenoid valve. A drive device for a solenoid valve, comprising: 2. A method according to claim 1, wherein said calibration information is feedback-controlled when said drive current is feedback-controlled so as to match a target flow rate or target pressure for inspection, and said target flow rate for inspection or said reference flow rate on said reference correlation. 2. The solenoid valve driving device according to claim 1, wherein the driving value is obtained in advance based on a deviation from a driving current corresponding to a target pressure. 3. The calibration information is obtained in advance by adjusting the flow rate or pressure of a fluid different from the fluid whose flow rate or pressure is adjusted by a solenoid valve, and the calibration information is used for a fluid whose flow rate or pressure is actually adjusted. 3. The driving device for a solenoid valve according to claim 2, wherein the driving value is converted into a value.